This invention relates to bulk current injection techniques for electromagnetic susceptibility testing.
Bulk current injection (BCI) techniques are widely used for equipment susceptibility testing in the automotive and aerospace industries. BCI involves injecting high-frequency electrical currents (e.g., 1 MHz-1 GHz) into wires connected to the equipment under test. A useful and properly designed BCI test setup provides valuable information on equipment susceptibility to induced high-frequency currents. High-frequency "noise" can be caused by many electrical events, such as, for example, high-voltage electrical ignition modules, relay coil and contact opening or closing, nearby lightning storms, and other transient electrical events.
Conventional BCI approaches inject a continuous high, radio frequency (RF) current into a wire under test. The induced current level required to create an electromagnetic susceptibility problem is often so large that the injected RF energy destroys the equipment under test. It is desirable to induce large currents for electromagnetic susceptibility testing, but with a sufficiently low effective duty cycle so that no permanent damage occurs to the equipment under test. Such a low-effective-duty-cycle injected waveform should induce no other currents than at the intended single injection frequency.